The prior art has seen a wide variety of different types of seals for sealing between a rod and head of a hydraulic cylinder through which it traverses. There have been many fewer sealing combinations developed, however, for sealing between a cable, even a plastic covered cable, traversing through the seal and the head of a hydraulic cylinder through which it traverses.
One of the approaches of the prior art has been the use of a plurality of compression seals in the form of an endless packing material that is wrapped around the cable, or a plurality of rings that can be split and then joined about the cable with their ends split in an offset pattern arrangement. Where the offset pattern arrangement of split ends is employed, there is usually employed a dam or the like intermediate the split ends to prevent liquids from flowing from one split end to another split end. The inventors do not know of another sealing arrangement in which a single split seal is employed as in the preferred embodiment of this invention.
In my U.S. Pat. No. 3,866,923, I disclosed a sealing rod wiper that was capable of alleviating problems due to intake of dust, water and the like and that invention is useful in this invention. Despite this improvement there continues to be problems with leakage of seals. In my U.S. Pat. No. 3,554,569, I described a dynamic pressure balanced seal that had very little leakage and that seal has proven useful in this invention. In my U.S. Pat. No. 4,476,772, I described an improved caging seal for hydraulic elevators or the like that resisted crushing of the seals. That approach proved satisfactory for elevator push rods that pushed the elevator upwardly and downwardly. It was not totally satisfactory, however, for a hydraulic seal in which cables traversed through the head of the cylinder, instead of having a steel rod or the like, it had a smooth external surface traversing through the head of the hydraulic cylinder.
From the foregoing it can be seen that the prior art has not provided an economical sealing combination that can be employed to seal intermediate a plastic covered cable and a head on a hydraulic cylinder encompassing a piston in in which the seal could be made to work with only a single split seal; thereby alleviating the deficiencies of the prior art and the necessity for using a plurality of sealing rings with dams intermediate splitting ends.